[AMD]add RDNA4 (gfx1200/gfx1201) support to ROCm7.2 setup

[Kaihui-AMD]

What this PR does

Adds RDNA4 support documentation for RX 9070 / RX 9070 XT (gfx1200 / gfx1201) to the AMD ROCm setup path, covering two gaps that currently cause silent failures for users on this hardware:

docs/SETUP.md — adds gfx1200 and gfx1201 rows to the AMD GPU targets table, with a note that RDNA4 requires ATLAS_ROCM_TAG=7.2.3-complete (the default ROCm 6.2 base image predates these targets).

docs/TROUBLESHOOTING.md — adds a ### RDNA4 (RX 9070 / 9070 XT) section with symptom, root cause, fix commands, and an explicit warning not to set ATLAS_HSA_OVERRIDE_GFX_VERSION — ROCm 7.0+ supports gfx1200/gfx1201 natively and overriding it causes a kernel/runtime target mismatch that crashes the container.

Testing

Tested on AMD Radeon AI PRO R9700 (gfx1201) with ATLAS_ROCM_TAG=7.2.3-complete and ATLAS_GFX_TARGET=gfx1201:

• Docker build completes successfully
• expose-hidden-states.patch applies cleanly to the pinned llama.cpp SHA
• Text generation inference works correctly
• Embedding endpoint (/v1/embeddings) works correctly — Geometric Lens path functional
• ATLAS_HSA_OVERRIDE_GFX_VERSION unset throughout; gfx1201 recognized natively by ROCm 7.2
• Tests: python tests/validate_tests.py — ✅ All tests pass integrity check

Checklist items from #26

• Add ROCm section to docs/SETUP.md
• Add ROCm troubleshooting to docs/TROUBLESHOOTING.md

[Kaihui-AMD]

Hi @itigges22, this PR covers the RDNA4 docs checklist from #26, tested on gfx1201 hardware. Let me know if you'd like any changes.